White balance adjusting device

Abstract

A white balance adjusting device comprising at least three optical sensors of different spectral sensitivity characteristics from one another, a computing circuit for calculating a ratio of outputs of the optical sensors, a ripple detecting circuit for determining whether or not light incident on the optical sensors contains ripples, a selecting circuit for selecting outputs of the computing circuit in accordance with an output of the ripple detecting circuit and a control signal forming circuit for producing control signals for controlling gains of color components of a color video signal in accordance with an output selected by the selecting circuit.

What is claimed is: 
     
       1. A white balance adjusting device comprising at least three optical sensors of different sensitivity characteristics from one another, computing means for calculating a ratio of outputs of said optical sensors, ripple detecting means for detecting whether or not light incident on said optical sensors contains ripples, selecting means for selecting outputs of said computing means in accordance with an output of said ripple detecting means, and control signal forming means for forming control signals for controlling gains of color components of a color video signal in accordance with an output selected by said selecting means. 
     
     
       2. A device according to claim 1, wherein said three optical sensors are R, G and B sensors. 
     
     
       3. A device according to claim 2, wherein said ripple detecting means detects ripples on the basis of outputs of said R sensor and said B sensor. 
     
     
       4. A device according to claim 1, wherein said selecting means has a first mode in which said control signals are formed by using outputs of said three optical sensors and a second mode in which said control signals are formed by using outputs of two of said optical sensors. 
     
     
       5. A device according to claim 4, wherein said three optical sensors are R, G and B sensors. 
     
     
       6. A device according to claim 5, wherein in said second mode, said selecting means selects outputs of said R sensor and said B sensor to be used in forming said control signals. 
     
     
       7. An image sensing apparatus comprising: (a) image sensing means for forming color video signals as an output signal;   (b) a plurality of different color sensors from each other;   (c) detecting means for detecting ripples of ambient light; and   (d) control means for varying a combination of outputs of said plurality of color sensors in accordance with an output of said detecting means to form control signals for controlling a color balance of the output signal of said image sensing means.   
     
     
       8. An apparatus according to claim 7, wherein said plurality of color sensors include R, G and B sensors. 
     
     
       9. An apparatus according to claim 8, wherein said detecting means detects ripples from outputs of said R sensor and said B sensor. 
     
     
       10. An apparatus according to claim 7, wherein said control means changes the number of outputs of said plurality of color sensors which are to be used for forming the control signals in accordance with the output of said detecting means. 
     
     
       11. An apparatus according to claim 10, wherein said plurality of color sensors include R, G and B sensors. 
     
     
       12. An apparatus according to claim 11, wherein said control means changes over between a mode in which the control signals are formed from outputs of said R, G and B sensors and another mode in which the control signals are formed from outputs of said R and B sensors in accordance with the output of said detecting means.